In the extended edition of the movie, Thrain is held captive at Dol Guldur, but in the book he is believed to have died long before the dwarves and Bilbo set off for Erebor.

电影的加长版里，瑟莱因成为了多尔哥多的俘虏，但是在书里，他在矮人和比尔博出发前往孤山之前就死了很久了。

youdao

In An Unexpected Journey, Baggins attempts to reclaim the lost Dwarf Kingdom of Erebor from Smaug, the dragon.

BBC: First instalment of The Hobbit to get Royal premiere

We soon learn about the dwarven kingdom of Erebor, a.k.a The Lonely Mountain, and Thror, its King Under the Mountain.

FORBES: Review: The Hobbit: An Unexpected, But Very Welcome, Journey